Translation:The currency of the United States is the dollar.
I thought it was just a statement. So I put: "Currency in the United States is the dollar." But it was DENIED ( imagine crying and sobbing sound effects ) ;)
I think it works with ambiguous sentences like "We live in America" or "I love America" where the speaker in fact means the US, but even if he doesn't, that could still be a true statement.
But here, it's different. Since Mexico, for example, doesn't have the Dollar, it can't be generally true for the whole continent, so 'America' doesn't really work here.